As a tank which is utilized for the storage of hydrogen or the like, there has been utilized a tank including a fiber reinforced plastics (FRP) layer formed by alternately laminating hoop layers and helical layers on the outer periphery of a liner (see e.g. Patent Document 1). The hoop layer is a layer formed by hoop-winding a bundle of fibers (e.g. carbon fibers) (a winding way of winding the bundle around a tank trunk part almost vertically to a tank axis), and the helical layer is a layer formed by helically winding a bundle of fibers such as carbon fibers (CF) (a winding way of winding the bundle up to a tank dome part almost in parallel with the tank axis) (see FIG. 2 of the present application).